Pneumatic for automatic player-pianos.



A. G. GULBRANSEN.

PNEUMATIC FOR AUTOMATIC PLAYER PIANOS.

APPLIUATION FILED DEC. 8, 1909.

998, 1 71 Patented July 18, 1911.

WITnE E 5 E3 5 InvEnTmT g a: Axel [3. E111 twins ED H A, AITEIT'HEL]?UNITED STATES PATENT OFFICE.

AXEL G. GULBRANSEN, OF CHICAGO, ILLINOIS, ASSIGNOR TO GULBRANSEN-"DICKINSON COMPANY, OF CHICAGO,'ILLINOIS, A CORPORATION OF ILLINOIS.

PNEUMATIC FOR AUTOMATIC P LAYEIt-PIANOS.

Specification of Letters Patent.

Patented July 18, 1911.

Application filed December 8, 1909. Serial No. 531,994.

To all whom it may concern:

Be it known that I, AXEL G. GULBRAN- spin, a citizen of the UnitedStates, residing at Chicago, in the county of Cook and State ofIllinols, have invented a certain new and useful Improvement inPneumatics for Automatic Piano-Players, of which the following is afull, clear, concise, and exact description, reference being had to theaccompanying drawings, forming a part of this specification. I

My invention relates to neumatics for automatic player pianos, and hasspecial reference to an improved form of valve which will allow moreeflicient operation of the pneumatic.

I have already described in previously issued patents the generalconstruction of my automatic player piano and the pneumatics associatedtherewith. Such descriptions will be found in the following patents:

874,675 of Dec. 24, 1907 874,762 of Dec. 24, 1907 874,763 of Dec. 24,1907 891,930 of June 30, 1908 913,378 of Feb. 23, 1909.

In the construction of the valve associated with the 'pneumatics, theform which I have preferably employed is constructed by interposing aleather washer between the end of the valve stem and the lever which isactuated by a rubber diaphragm moved by the pressure of air flowing tothe pneulnatic from an opening corresponding to any given note in thetracker board mechanism. The leather washer has been glued to the leverabove mentioned, and-the end of the stern in turn glued to the leatherwasher. At the other end of the stem a valve button has been attached, asecond leather washer being inserted and glued on its two sides to thevalve button and the end of the valve stem respectively. On each end thevalve stem has been squarely cut off. I have found that according tothis construction there is a tendency for the valve stem to be displacedfrom its normal position, with the result that the valve button does notbecome seated evenly and satisfacto-rily on the valve seat.

According to my present improvement, the lower end :of the valve stem issquarely out off and is glued or otherwise-suitably attached directly tothe lever above mentioned. The upper end of the valve stem is rounded",and the valve button on the under side of which a leather washer is.attached, is glued or otherwise suitably fastened to the rounded upperend of the valve stem through the medium of this washer. According tothis construction it will be apparent that the valve stem is rigidlymounted with respect to the lever, and for this reason it will alwaysoperate in a true and accurate manner, and no guides are necessary, suchas are often used in connection with the primary valves of thepneumatics of other construction. On account of the rounded form of theupper end of the valve stem the valve button is allowed to adjust itselfwith great ease to the valve seat, and always forms a tight and accuratejoint. I have found that by means of the improvement above described theoperatin piano is considerably increased. These and other advantages ofmy invention will be more readily understood by reference to theaccompanying drawings, in which Figure 1 is a plan and partly sectionalview of a single pneumat c showing the valve in position. Fig. 2 is asectional view on the line 22 of Fig. 1.

The neumatic has a main mounting block 1 from the lower side of which issuspended a bellows 2. In the drawings I have shown only a singlebellows, but it will. be understood that any number could be attached ina vertical series to the main mounting block, the lower swinging member3 of each bellows being connected by a suitable lever mechanism with theswinging member 3 next above. This construction has been described indetail in the patents which I have mentioned above. The swinging member3 is hinged tothe main mounting block 1 by means of the hinge 4,preferably constructed of some suitable cloth and glued to the partswhich are thus connected.

Attached to the main mounting block 1 by means of screws 5 is the valveblock 5. A leather strip (3 is glued to the ends of valve block 5 andmain mounting block 1, as clearly shown in Figs. 1 and 2 Within thevalve block 5 is a valve chamber 7 which is covered by means of leatherwasher 8, in

'a means ofcommunication between the for example, 8 l-,7(l3, of December2st, 1907,

19 of cloth "mounted nearer the hinged end of the lever.

mounted yvithin the valve block 5 and forms valve chamber? and the upperdiaphragm chamber 11 within the main mounting block 1. As shown in. Fig.2, the ring extends slightly above the bottom of valve chamber 7 andforms a valve seat on which a leather washer 12 attached to the underside of valve button 13 is adapted to be seated.

As shown by the dotted lines in Fig. I, the upper- ..diaphragm chamber11 in the main mounting block 1 is circular in shape and communicates bymeans of the passage 14 and the opening 15 in the leather strip 6 withthe low-pressure chamber which has been described in my previouspatents, as,

but which, for. the sake of simplicity, is omitted from the presentdrawing.

The upper diaphragm chamber ll has its bottom covered by the disk 15 ofrubber or other flexible material, this disk bcing glued to the annularraised portion 16 which encircles the diaphragm chamber. Glued ,to theupper surface of the diaphragm near its center is the leather or felt.washer 17." To the upper part of this washer is glued the lever 18, theother end oi which is similarly attached to the hinge or other flexiblematerial, this hinge being attached to the bottom of passage 14.

At or near the end of lever 18 is glued the valve stem 20, this stembeing directly mounted on the lever with no intervening washer ofleather or other material. The upper end of valve stem 20 is rounded asshown in Fig. 2, and the leather washer 12 is glued to this rounded endofthe valve stem. It will be observed that the end of lever 18 to whichthe valve stem 20 is at ltlCllCtl extends considerably beyond the middleof the diaphragm 15. The bject of this construction is to ail'ord agreater degree of movement for the valve stem 20 and its associatedvalve button 13 than would be the case were the valve stem Below thediaphragn'i 15 is the lower diaphragm chamber 21, communication of whichwith the bellows is prevented by means of the disk 22. Connecting withthe lower diaphragm chamber 21 is the passage 23, which is connected bysuitable means which i have described in my previous patents, with anopening in the tracker-board which is assigned to the hammer of thepiano which the pneumatic is arranged to operate.

The inside of bellows communicates through passages 24 in the mainmounting block 1 and the valve block 5 with the valve chamber 7.

The operation of the pneumatic will now be clearly understood. Inasmuchas valve chamber 7 communicates through opening 9 with the atmosphere itis evident that atmospheric pressure will 'pass' to bellows which willthereby be kept in its distended condition as shown in Fig. 2. Upper diaphragm chamber ll, as explained above, is constantly in directcomn'nmication with a low pressure chamber, and is sealed against theadmission of air by the seating of valve button 13 on its seat 10. Whenan opening in the music roll comes opposite the appropriate opening inthe trackerdioard, air is admitted, by means which have been describedin my previous patents, into passage 23 and lower diaphragm chamber 2)..

The diaphragm 15 is thereby forced upwardly, and by the action of lever18 the valve button 13 is unseated from its valve seat 10, and thecommunication of valve chamber 7 with atmq sphere is cut oil by theseating of valve button 13 against the washer S. l t is now evident thatcommunication is established between valve chamber 7 and the lowpressure chamber through upper diaphragm chamber 11., passage 14:

.and opening 15 in the leather strip. This connnunicatnm with the lowpressure chamber :.'.so extends through passages 24 to the bellows 2,which is thereby contracted, and the swinging member 3 is raised untildisk comes in contact with the lower end of screw 26 which passesthrough the main mounting block 1. he end 27 of swinging member 3 isadapted to come in contactwith a suitable abutment member on an abstractrod, and the note is thereby sounded. The construction is precisely thesame in principle as it, instead of a single pneumatic, a series or tierof pneumatics is used. lVhen air no longer passes through passage 23into lower diaphragm chamber 21 the diaphragm 15 again passes into itsposition shown in Fig. 2, and the normal positions of the various partsa re again assumed.

Certain changes could be made in the exact construction of the partswhich I have described without departii'ig from the spirit of myinvention.

hat I claim' is:

1; In an automatic piano,- an actuating valve stem having a rounded end,and a valve in the form of a button having a flexible part secured tosaid rounded end of said valve stem.

2. In an automatic piano, an actuating valve stem, the top of said valvestem being rounded, a 'alve in the form of a button having a disk offlexible material secured to the under side thereof, said disk oiflexible material being glued to a considerablearea of the rounded endof said valve stem.

3. in pneumatic action mechanism for mechanically operated musicalinstruments, the combination with the bellows, oi a valve forcontrolling the bellows, a valve stem with a II. 1. O

rounded end to which said valve is flexibly secured, a lever to whichsaid valve stem is rigidly attached, and a diaphragm for operating saidlever, said lever being hinged at one side of said diaphragm andextending over the same and said stein being secured to said leverbeyond the point of connection between said diaphragm and said lever.

4. In an automatic piano, an actuating lever, a valve stem rigidlysecured. to said lever, said stem having a rounded end, a valve in theform of a button having a flexible disk secured to said rounded end ofsaid valve stem, and a bellows-controlled I by said valve.

